I ask this because I want to find a better way to create backups than storing them on DVD. For example, I am considering to buy the Freecom Hard Drive Dock, a product which is made with this purpose in mind.

This question appears to be off-topic. The users who voted to close gave these specific reasons:

"Questions seeking for hardware shopping recommendations are off-topic because they are often relevant only to the question author at the time the question was asked and tend to become obsolete quickly. Instead of asking what to buy, try asking how to find out what suits your needs." – Journeyman Geek, Sathya

"This question is not about computer hardware or software, within the scope defined in the help center." – Tog, ultrasawblade